Schweizer's_reagent
Schweizer's reagent
Chemical compound
Schweizer's reagent is a metal ammine complex with the formula [Cu(NH3)4(H2O)2](OH)2. This deep-blue compound is used in purifying cellulose. This salt consists of tetraamminediaquacopper(II) cations ([Cu(NH3)4(H2O)2]2+) and hydroxide anions (OH−).
It is prepared by dissolving copper(II) hydroxide in an aqueous solution of ammonia.
It forms an azure solution. Evaporation of these solutions leaves light blue residue of copper hydroxide, reflecting the lability of the copper-ammonia bonding. If conducted under a stream of ammonia, then deep blue needle-like crystals of the tetrammine form. In presence of oxygen, concentrated solutions give rise to nitrites Cu(NO2)2(NH3)n. The nitrite results from oxidation of the ammonia.[1][2]